Longterm objectives are: (1) development of an inexpensive, MRI tissueequivalent material; (2) construction of MRI quality assurance standards; (3) development of complex tissueequivalent anthropomorphic MRI phantoms to aid in detection of pathological conditions. Goals (1) and (2) alone will benefit the health care industry through the development of innovative technology which will produce complex performance phantoms to aid in the assessment of new MRI diagnostic instrumentation and provide quality assurance for existing systems. Attainment of goal (3) will help improve clinical diagnostic methods leading to improved, lower cost patient care. Goal attainment is predicated upon development of a suitable MRI tissueequivalent substance(s). Preliminary experiments indicate that gel/water composites composed of a modified polysaccharide, used in RFmicrowave hyperthermia phantoms, and appropriate modifying agents show promise as MRI tissueequivalents. Phase I will involve (1) systematic evaluation of the NMR properties of this material using a 760 MHz pulsed NMR spectrometer; (2) construction of tissuelike composites and the evaluation of their imaging qualities and stability using a 0,5 Tesla MRI device. Concurrently, novel molding techniques to produce contiguous regions of dissimilar NMR will be examined.